{"id":3240,"date":"2017-03-03T00:35:11","date_gmt":"2017-03-02T16:35:11","guid":{"rendered":"https:\/\/ixyzero.com\/blog\/?p=3240"},"modified":"2017-03-03T00:35:11","modified_gmt":"2017-03-02T16:35:11","slug":"buffer%e5%92%8ccache","status":"publish","type":"post","link":"https:\/\/ixyzero.com\/blog\/archives\/3240.html","title":{"rendered":"Buffer\u548cCache"},"content":{"rendered":"<p>=Start=<\/p>\n<h4>\u7f18\u7531\uff1a<\/h4>\n<p>\u5728\u590d\u4e60Linux\u7684\u5185\u5b58\u76f8\u5173\u77e5\u8bc6\u65f6\u60f3\u5230\u7684\u95ee\u9898\uff0cBuffer\u548cCache\u5206\u522b\u662f\u4ec0\u4e48\uff1f\u53c8\u6709\u54ea\u4e9b\u533a\u522b\u548c\u8054\u7cfb\uff1f<\/p>\n<h4>\u6b63\u6587\uff1a<\/h4>\n<h5>\u53c2\u8003\u89e3\u7b54\uff1a<\/h5>\n<p>\u9996\u5148\u4ece\u7ffb\u8bd1\u4e0a\uff0cBuffer\u5e94\u8be5\u7ffb\u8bd1\u4e3a\u201c\u7f13\u51b2\u201d\uff0cCache\u5e94\u8be5\u7ffb\u8bd1\u4e3a\u201c\u7f13\u5b58\u201d\uff0c\u4e24\u4e2a\u5b8c\u5168\u4e0d\u662f\u4e00\u4e2a\u4e1c\u897f\u3002<\/p>\n<p><span style=\"color: #ff0000;\"><strong>\u4ece\u786c\u4ef6\u8fd9\u4e00\u5c42\u6765\u770b<\/strong><\/span>\uff0cBuffer\u5e94\u8be5\u4e3a\u5185\u5b58\uff0cCache\u4e3aCPU\u96c6\u6210\u7684\u9ad8\u901f\u7f13\u5b58\u3002<\/p>\n<ul>\n<li>Buffer\u662f\u4e3a\u4e86\u8ba9\u4e0d\u540c\u901f\u5ea6\u7684\u8bbe\u5907\u80fd\u591f\u540c\u6b65\uff0c\u5efa\u7acb\u7684\u4e00\u4e2a\u7f13\u51b2\u533a\u57df\uff0c\u5199\u8fdbBuffer\u7684\u6570\u636e\u662f\u4e3a\u4e86\u4ece\u4e2d\u62ff\u51fa\u5199\u5165\u5176\u4ed6\u8bbe\u5907\u3002<\/li>\n<li>Cache\u662f\u4e3a\u4e86\u63d0\u9ad8\u8bfb\u53d6\u901f\u5ea6\uff0c\u5c06\u7ecf\u5e38\u6216\u9a6c\u4e0a\u9700\u8981\u7684\u6570\u636e\u9884\u8bfb\u5230\u7f13\u5b58\u4e2d\uff0c\u5199\u8fdbCache\u7684\u6570\u636e\u662f\u4e3a\u4e86\u5176\u4ed6\u8bbe\u5907\u4ece\u4e2d\u53bb\u8bfb\u53d6\u3002<\/li>\n<\/ul>\n<p><span style=\"color: #ff0000;\"><strong>\u4ece\u8f6f\u4ef6\u8fd9\u4e00\u5c42\u6765\u8bf4<\/strong><\/span>\uff0cBuffer\u662f\u5757\u8bbe\u5907\u7684\u7f13\u51b2\uff0cCache\u662f\u6587\u4ef6\u7cfb\u7edf\u7684\u7f13\u5b58\u3002\u4ee5Linux\u4e3a\u4f8b\uff1a<\/p>\n<ul>\n<li>Buffer(Buffer Cache)\u4ee5\u5757\u5f62\u5f0f\u7f13\u51b2\u4e86\u5757\u8bbe\u5907\u7684\u64cd\u4f5c\uff0c\u5b9a\u65f6\u6216\u624b\u52a8\u7684\u540c\u6b65\u5230\u786c\u76d8\uff0c\u5b83\u662f\u4e3a\u4e86\u7f13\u51b2\u5199\u64cd\u4f5c\u7136\u540e\u4e00\u6b21\u6027\u5c06\u5f88\u591a\u6539\u52a8\u5199\u5165\u786c\u76d8\uff0c\u907f\u514d\u9891\u7e41\u5199\u786c\u76d8\uff0c\u63d0\u9ad8\u5199\u5165\u6548\u7387\u3002<\/li>\n<li>Cache(Page Cache)\u4ee5\u9875\u9762\u5f62\u5f0f\u7f13\u5b58\u4e86\u6587\u4ef6\u7cfb\u7edf\u7684\u6587\u4ef6\uff0c\u7ed9\u9700\u8981\u4f7f\u7528\u7684\u7a0b\u5e8f\u8bfb\u53d6\uff0c\u5b83\u662f\u4e3a\u4e86\u7ed9\u8bfb\u64cd\u4f5c\u63d0\u4f9b\u7f13\u51b2\uff0c\u907f\u514d\u9891\u7e41\u8bfb\u786c\u76d8\uff0c\u63d0\u9ad8\u8bfb\u53d6\u6548\u7387\u3002<\/li>\n<\/ul>\n<p>\u603b\u800c\u8a00\u4e4b\uff0c<span style=\"color: #ff0000;\">Buffer\u91cc\u9762\u7684\u4e1c\u897f\u662f\u4e3a\u4e86\u5199\u5230\u522b\u5904\u53bb\uff0cCache\u91cc\u9762\u7684\u4e1c\u897f\u662f\u4e3a\u4e86\u7ed9\u522b\u5904\u8bfb<\/span>\u3002<\/p>\n<hr \/>\n<h6>cache<\/h6>\n<p>cache \u5c31\u662f\u7f13\u5b58\u7684\u610f\u601d\u3002\u5f53\u7cfb\u7edf\u8bfb\u6587\u4ef6\u7684\u65f6\u5019\uff0c\u90fd\u662f\u628a\u6570\u636e\u4ece\u786c\u76d8\u8bfb\u5230\u5185\u5b58\u91cc\uff0c\u56e0\u4e3a\u786c\u76d8\u6bd4\u5185\u5b58\u6162\u5f88\u591a\uff0c\u6240\u4ee5\u8fd9\u4e2a\u8fc7\u7a0b\u4f1a\u5f88\u8017\u65f6\u3002\u4e3a\u4e86\u63d0\u9ad8\u6548\u7387\uff0cLinux \u4f1a\u628a\u8bfb\u8fdb\u6765\u7684\u6587\u4ef6\u5728\u5185\u5b58\u4e2d\u7f13\u5b58\u4e0b\u6765\uff08\u56e0\u4e3a\u8bfb\u53d6\u76f8\u8fd1\u90e8\u5206\u7684\u5185\u5bb9\u662f\u7a0b\u5e8f\u5f88\u5e38\u89c1\u7684\u60c5\u51b5\uff09\uff0c\u5373\u4f7f\u7a0b\u5e8f\u7ed3\u675f\uff0ccache \u4e5f\u4e0d\u4f1a\u88ab\u81ea\u52a8\u91ca\u653e\u3002\u6240\u4ee5\u5462\uff0c\u5982\u679c\u6709\u7a0b\u5e8f\u8fdb\u884c\u5927\u91cf\u7684\u8bfb\u6587\u4ef6\u64cd\u4f5c\uff0c\u4f60\u4f1a\u53d1\u73b0\u5185\u5b58\u4f7f\u7528\u7387\u5c31\u4e0a\u53bb\u4e86\u3002<\/p>\n<p>\u4e0d\u8fc7\u4e5f\u4e0d\u7528\u62c5\u5fc3\uff0c\u5982\u679c\u5176\u4ed6\u7a0b\u5e8f\u4f7f\u7528\u8981\u4f7f\u7528\u5185\u5b58\u7684\u65f6\u5019\uff0clinux \u4e5f\u4f1a\u628a\u8fd9\u4e9b\u6ca1\u4eba\u4f7f\u7528\u7684 cache \u91ca\u653e\u6389\uff0c\u7ed9\u5176\u4ed6\u8fd0\u884c\u7684\u7a0b\u5e8f\u4f7f\u7528\u3002\u5f53\u7136\u4f60\u4e5f\u53ef\u4ee5\u624b\u52a8\u53bb\u91ca\u653e\u6389\u8fd9\u90e8\u5206\u5185\u5b58\uff1a<\/p>\n<p><code>echo 1 &gt; \/proc\/sys\/vm\/drop_caches<\/code><\/p>\n<h6>buffer<\/h6>\n<p>buffer \u7684\u610f\u601d\u548c cache \u76f8\u8fd1\uff0c\u4e0d\u8fc7\u7a0d\u6709\u533a\u522b\u3002\u8003\u8651\u5185\u5b58\u5199\u6587\u4ef6\u5230\u786c\u76d8\u7684\u8fc7\u7a0b\uff0c\u56e0\u4e3a\u786c\u76d8\u592a\u6162\u4e86\uff0c\u5982\u679c\u5185\u5b58\u8981\u7b49\u5f85\u6570\u636e\u5199\u5b8c\u4e4b\u540e\u624d\u7ee7\u7eed\u540e\u9762\u7684\u64cd\u4f5c\uff0c\u5b9e\u5728\u662f\u6548\u7387\u5f88\u4f4e\u7684\u4e8b\u60c5\uff0c\u4e5f\u4f1a\u5f71\u54cd\u7a0b\u5e8f\u7684\u8fd0\u884c\u901f\u5ea6\u3002\u6240\u4ee5\u5c31\u6709\u4e86 buffer\uff0c\u5199\u5230\u786c\u76d8\u7684\u6570\u636e\u4f1a\u653e\u5230 buffer \u91cc\u9762\uff0c\u5185\u5b58\u5f88\u5feb\u628a\u6570\u636e\u5199\u5230 buffer\uff0c\u53ef\u4ee5\u7ee7\u7eed\u5176\u4ed6\u7684\u5de5\u4f5c\uff0c\u800c\u786c\u76d8\u53ef\u4ee5\u5728\u540e\u53f0\u6162\u6162\u8bfb\u51fa buffer \u4e2d\u7684\u6570\u636e\uff0c\u4fdd\u5b58\u8d77\u6765\u3002\u8fd9\u6837\u5c31\u63d0\u9ad8\u4e86\u8bfb\u5199\u7684\u6548\u7387\uff01<\/p>\n<p>\u8bb2\u4e00\u4e2a\u5927\u5bb6\u4f1a\u7ecf\u5e38\u9047\u5230\u7684\u4f8b\u5b50\uff0c\u5f53\u6211\u4eec\u628a\u7535\u8111\u91cc\u4e2d\u7684\u6587\u4ef6\u62f7\u8d1d\u5230 U \u76d8\u7684\u65f6\u5019\uff0c\u5982\u679c\u6587\u4ef6\u7279\u522b\u5927\uff0c\u5927\u5bb6\u4f1a\u9047\u5230\u8fd9\u79cd\u60c5\u51b5\uff1a\u660e\u660e\u770b\u5230\u6587\u4ef6\u5df2\u7ecf\u62f7\u8d1d\u5b8c\u4e86\uff0c\u4f46\u7cfb\u7edf\u8fd8\u662f\u4f1a\u63d0\u793a U \u76d8\u6b63\u5728\u4f7f\u7528\u4e2d\u3002\u8fd9\u5c31\u662f buffer \u7684\u539f\u56e0\uff0c\u62f7\u8d1d\u7a0b\u5e8f\u628a\u4e1c\u897f\u653e\u5230 buffer \u4e4b\u540e\uff0c\u4f46\u662f U \u76d8\u8fd8\u6ca1\u6709\u5199\u5b8c\u3002<\/p>\n<p>\u540c\u6837\u7684\uff0c\u53ef\u4ee5\u624b\u52a8\u6765 flush buffer \u7684\u5185\u5bb9\uff0c\u4f7f\u7528\u7684\u547d\u4ee4\u662f\uff1a<\/p>\n<p><code>sync<\/code><\/p>\n<hr \/>\n<h6>Page Cache\u548cBuffer Cache\u7684\u533a\u522b<\/h6>\n<p><span style=\"color: #ff0000;\">Page Cache\u5b9e\u9645\u4e0a\u662f\u9488\u5bf9\u6587\u4ef6\u7cfb\u7edf\u7684\uff0c\u662f\u6587\u4ef6\u7684\u7f13\u5b58\uff0c\u5728\u6587\u4ef6\u5c42\u9762\u4e0a\u7684\u6570\u636e\u4f1a\u7f13\u5b58\u5230page cache\u3002<\/span>\u6587\u4ef6\u7684\u903b\u8f91\u5c42\u9700\u8981\u6620\u5c04\u5230\u5b9e\u9645\u7684\u7269\u7406\u78c1\u76d8\uff0c\u8fd9\u79cd\u6620\u5c04\u5173\u7cfb\u7531\u6587\u4ef6\u7cfb\u7edf\u6765\u5b8c\u6210\u3002\u5f53page cache\u7684\u6570\u636e\u9700\u8981\u5237\u65b0\u65f6\uff0cpage cache\u4e2d\u7684\u6570\u636e\u4ea4\u7ed9buffer cache\uff0c\u4f46\u662f\u8fd9\u79cd\u5904\u7406\u57282.6\u7248\u672c\u7684\u5185\u6838\u4e4b\u540e\u5c31\u53d8\u7684\u5f88\u7b80\u5355\u4e86\uff0c\u6ca1\u6709\u771f\u6b63\u610f\u4e49\u4e0a\u7684cache\u64cd\u4f5c\u3002<\/p>\n<p><span style=\"color: #ff0000;\">Buffer Cache\u662f\u9488\u5bf9\u78c1\u76d8\u5757\u7684\u7f13\u5b58\uff0c\u4e5f\u5c31\u662f\u5728\u6ca1\u6709\u6587\u4ef6\u7cfb\u7edf\u7684\u60c5\u51b5\u4e0b\uff0c\u76f4\u63a5\u5bf9\u78c1\u76d8\u8fdb\u884c\u64cd\u4f5c\u7684\u6570\u636e\u4f1a\u7f13\u5b58\u5230buffer cache\u4e2d<\/span>\uff0c\u4f8b\u5982\uff0c\u6587\u4ef6\u7cfb\u7edf\u7684\u5143\u6570\u636e\u90fd\u4f1a\u7f13\u5b58\u5230buffer cache\u4e2d\u3002<\/p>\n<p><strong>\u7b80\u5355\u8bf4\u6765\uff0cpage cache\u7528\u6765\u7f13\u5b58\u6587\u4ef6\u6570\u636e\uff0cbuffer cache\u7528\u6765\u7f13\u5b58\u78c1\u76d8\u6570\u636e\u3002<\/strong>\u5728\u6709\u6587\u4ef6\u7cfb\u7edf\u7684\u60c5\u51b5\u4e0b\uff0c\u5bf9\u6587\u4ef6\u64cd\u4f5c\uff0c\u90a3\u4e48\u6570\u636e\u4f1a\u7f13\u5b58\u5230page cache\uff0c\u5982\u679c\u76f4\u63a5\u91c7\u7528dd\u7b49\u5de5\u5177\u5bf9\u78c1\u76d8\u8fdb\u884c\u8bfb\u5199\uff0c\u90a3\u4e48\u6570\u636e\u4f1a\u7f13\u5b58\u5230buffer cache\u3002<\/p>\n<h5>\u53c2\u8003\u94fe\u63a5\uff1a<\/h5>\n<ul>\n<li>Buffer\u4e0eCache<br \/>\n<a href=\"http:\/\/www.penglixun.com\/tech\/system\/buffer_and_cache_diff.html\">http:\/\/www.penglixun.com\/tech\/system\/buffer_and_cache_diff.html<\/a><\/li>\n<li>Page Cache\u548cBuffer Cache\u7684\u533a\u522b<br \/>\n<a href=\"http:\/\/www.penglixun.com\/tech\/system\/the_diffrents_of_page_cache_and_buffer_cache.html\">http:\/\/www.penglixun.com\/tech\/system\/the_diffrents_of_page_cache_and_buffer_cache.html<\/a><\/li>\n<li>\u901a\u8fc7 free \u547d\u4ee4\u7406\u89e3 linux \u5185\u5b58\u7ba1\u7406<br \/>\n<a href=\"http:\/\/cizixs.com\/2015\/10\/01\/linux-memory-management-through-free\">http:\/\/cizixs.com\/2015\/10\/01\/linux-memory-management-through-free<\/a><\/li>\n<li>Meaning of the buffers\/cache line in the output of free<br \/>\n<a href=\"http:\/\/serverfault.com\/questions\/85470\/meaning-of-the-buffers-cache-line-in-the-output-of-free\">http:\/\/serverfault.com\/questions\/85470\/meaning-of-the-buffers-cache-line-in-the-output-of-free<\/a><\/li>\n<li>In Linux, what is the difference between \u201cbuffers\u201d and \u201ccache\u201d reported by the free command?<br \/>\n<a href=\"http:\/\/serverfault.com\/questions\/23433\/in-linux-what-is-the-difference-between-buffers-and-cache-reported-by-the-f\">http:\/\/serverfault.com\/questions\/23433\/in-linux-what-is-the-difference-between-buffers-and-cache-reported-by-the-f<\/a><\/li>\n<li>Linux memory: buffer vs cache<br \/>\n<a href=\"http:\/\/stackoverflow.com\/questions\/6345020\/linux-memory-buffer-vs-cache\">http:\/\/stackoverflow.com\/questions\/6345020\/linux-memory-buffer-vs-cache<\/a><\/li>\n<li>The buffer cache<br \/>\n<a href=\"http:\/\/www.tldp.org\/LDP\/sag\/html\/buffer-cache.html\">http:\/\/www.tldp.org\/LDP\/sag\/html\/buffer-cache.html<\/a><\/li>\n<li>\u3010linux\u3011free\u547d\u4ee4\u4e2dcached\u548cbuffers\u7684\u533a\u522b<br \/>\n<a href=\"http:\/\/www.cnblogs.com\/chenpingzhao\/p\/5161844.html\">http:\/\/www.cnblogs.com\/chenpingzhao\/p\/5161844.html<\/a><\/li>\n<li>Linux Cache \u673a\u5236\u63a2\u7a76<br \/>\n<a href=\"http:\/\/www.penglixun.com\/tech\/system\/linux_cache_discovery.html\">http:\/\/www.penglixun.com\/tech\/system\/linux_cache_discovery.html<\/a><\/li>\n<\/ul>\n<p>=END=<\/p>\n","protected":false},"excerpt":{"rendered":"<p>=Start= \u7f18\u7531\uff1a \u5728\u590d\u4e60Linux\u7684\u5185\u5b58\u76f8\u5173\u77e5\u8bc6\u65f6\u60f3\u5230\u7684\u95ee\u9898\uff0cBuffer\u548cCache\u5206\u522b\u662f\u4ec0\u4e48\uff1f\u53c8\u6709\u54ea [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23,11],"tags":[763,764,766,30,765],"class_list":["post-3240","post","type-post","status-publish","format-standard","hentry","category-knowledgebase-2","category-linux","tag-buffer","tag-cache","tag-drop_caches","tag-linux","tag-sync"],"views":3221,"_links":{"self":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts\/3240","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/comments?post=3240"}],"version-history":[{"count":1,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts\/3240\/revisions"}],"predecessor-version":[{"id":3241,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts\/3240\/revisions\/3241"}],"wp:attachment":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/media?parent=3240"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/categories?post=3240"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/tags?post=3240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}